The incidence and clinical significance of incidental findings seen on pre-operative CT planning scans for hip and knee robotic arthroplasty surgery

Aim

The incidence and clinical significance of incidental findings identified on preoperative computerised tomography (CT) planning scans for hip and knee robotic arthroplasty is disputed. This study aimed to determine this within a single hip and knee arthroplasty unit.

Methods

A retrospective cohort study was performed for all patients that underwent CT planning scans for hip or knee arthroplasty at our institution over a 30-month period (Dec 2021–May 2024). CT scan reports were reviewed and incidental findings noted. Incidental findings were graded by independent reviewers into one of three categories: no action required, further action may be considered, urgent action required e.g. potential malignancy.

Results

1452 CT arthroplasty planning scans were identified over a 30-month period. A radiologist report was not provided in 48 (3.3 %) cases, leaving 1404 (96.7 %) available for further analysis. 592 (42.2 %) incidental findings were noted, of which 244 (17.4 %) were graded further action may be considered and 16 (1.1 %) urgent action required. All patients identified as urgent action required received appropriate management.

Conclusion

Pre-operative CT arthroplasty planning scans have a high incidence (N = 592, 42.2 %) of incidental findings, most of which most require no further management. A significant proportion (N = 244, 17.4 %) of scans have incidental findings for which further action may be considered, whilst a small proportion (N = 16, 1.1 %) have incidental findings for which urgent action is required. Pre-operative CT planning scans should be reported by a radiologist due to the high incidence of significant incidental findings.